This Chaos Deconstruction puzzle is named after a boss in Paper Mario: The Thousand-Year Door.
Fill some cells in the grid with the digits 1-9 such that no digit repeats in a row or column, and some cells are left empty.
All empty cells in the grid must be orthogonally connected.
All digits must belong to a region, which is an orthogonally connected group of 9 non-empty cells. Digits may not repeat in a region. Regions may not touch each other orthogonally.
Clues outside the grid give the sum of the digits before the first empty cell seen from that direction.
A digit in a circle indicates how many of the 8 surrounding cells are empty. A cell with a circle must contain a digit. Not all circles are necessarily given.
Here is an example puzzle on a 6x6 grid with the digits 1-4:
